The 'Maca Craca' is a 100% Australian Made Macadamia Nut Cracker. Designed to house the nut inside the stainless steel tube, when you give it a hit with the hammer, shell and bits don't go flying everywhere. Very fast and efficient, easy to use. It may take a few goes to get the 'feel' of how hard to hit with your hammer... most batches of nuts usually require the same amount of force to crack, so a bit of experimentation may be required. You can have 20 nuts cracked in the time it takes to use the screw type crackers, don't have to worry about finding the 'sweet spot'.